An investigation of the secretions of the potato cyst nematode Globodera pallida
Initial experiments performed in this study allowed species differentiation of Globodera pallida and G. rostochiensis following immunoblotting with the lectin, wheat germ agglutinin (WGA), and the monoclonal antibody TEPC 15. Further studies were aimed at the isolation of amphidial secretions. Two methods of collecting secretions were attempted, one involving the modification of a previously described staining method, the other relying on the collection of ES products from living, sterile nematodes. Secretions collected from G. pallida using the two different methods were analysed using SDS-PAGE electrophoresis. Secretions were also used for anti-serum production, giving two anti-sera, Luffness anti-serum and ES anti-serum. These were subsequently used for immunoblotting and indirect immunofluorescence studies. Indirect immunofluorescence studies indicated that the two anti-sera recognised different nematode components. This was further confirmed by immunoblotting studies which revealed that Luffness anti-serum recognised a number of nematode proteins, and was capable of differentiating both between and with species of G. pallida and G. rostochiensis. In contrast, ES anti-serum recognised only two proteins which appeared to be conserved between the two species. Observations also indicated that presence of a nematode lectin component present in amphidial secretions with apparent specificity for N-acetylgalactosamine. Experiments were also performed to examine different methods of inducing secretions. Previous research (Goverse et al., 1994) has shown that the serotonin agonist 5-methoxy dimethyl tryptamine (DMT) is an effective inducer of nematode oesophageal secretions. Comparison of DMT-induced secretions with ES secretions using SDS-PAGE electrophoresis revealed that the protein profiles were similar, although some proteins were more abundant following induction with DMT. Treatment of G. pallida with DMT followed by indirect immunofluorescence with Luffness anti-serum revealed an increased and altered distribution of antibody binding on the nematode surface.